In Vivo Investigation of Changes in Biomarkers of Oxidative Stress Induced by Plant Food Rich Diets
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- 作者：Henry J. Thompson ; Jerianne Heimendinger ; Cynthia Gillette ; Scot M. Sedlacek ; Albert Haegele ; Caitlin O'Neill ; and Pamela Wolfe
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2005
- 出版时间：July 27, 2005
- 年：2005
- 卷：53
- 期：15
- 页码：6126 - 6132
- 全文大小：284K
- 年卷期：v.53,no.15(July 27, 2005)
- ISSN：1520-5118
文摘
It is well established that vegetables and fruit (VF) contain antioxidant phytochemicals. Consequently,it is expected that individuals who consume diets with a high content of VF should be better protectedagainst oxidative cellular damage than individuals who do not, but not all data support this assumption.The objective of this study was to identify possible explanations for this conundrum. The effects oftwo diets that differed in VF content on markers of oxidative damage were studied. Sixty-four womenparticipated in a 14-day dietary intervention. Subjects consumed on average either 3.6 or 12.1 servingsof VF per day. The primary end points assessed were 8-hydroxy-2-deoxyguanosine (8-oxo-dG) inperipheral lymphocyte DNA and 8-isoprostaglandin F-2
(8-iso-PGF2) excreted in urine. Subjectsconsuming the high versus low VF diet had lower concentrations of 8-oxo-dG (p < 0.01) and of8-iso-PGF2 (p < 0.01). However, the reduction in oxidative end points by high VF was not uniform.Rather, an antioxidant effect was observed primarily in individuals whose oxidative end points atbaseline were above the median for the study population. Using change in plasma carotenoids (endpoint minus baseline measurements) as an index of phytochemical intake, the reduction in oxidativemarkers was inversely proportional to change in plasma carotenoids; this effect was stronger forlipid peroxidation (p < 0.01) than DNA oxidation (p < 0.05). These findings imply that increasingexogenous antioxidant exposure may primarily benefit individuals with elevated levels of oxidativestress. Null findings do not necessarily indicate that an antioxidant compound lacks in vivo activity.Keywords: Antioxidant; fruit; oxidative stress; DNA oxidation; lipid peroxidation; phytochemicals;vegetables
(8-iso-PGF2) excreted in urine. Subjectsconsuming the high versus low VF diet had lower concentrations of 8-oxo-dG (p < 0.01) and of8-iso-PGF2 (p < 0.01). However, the reduction in oxidative end points by high VF was not uniform.Rather, an antioxidant effect was observed primarily in individuals whose oxidative end points atbaseline were above the median for the study population. Using change in plasma carotenoids (endpoint minus baseline measurements) as an index of phytochemical intake, the reduction in oxidativemarkers was inversely proportional to change in plasma carotenoids; this effect was stronger forlipid peroxidation (p < 0.01) than DNA oxidation (p < 0.05). These findings imply that increasingexogenous antioxidant exposure may primarily benefit individuals with elevated levels of oxidativestress. Null findings do not necessarily indicate that an antioxidant compound lacks in vivo activity.Keywords: Antioxidant; fruit; oxidative stress; DNA oxidation; lipid peroxidation; phytochemicals;vegetables